package com.dfhz.ken.zermall.utils;

public class Base64Coder {
	private static final String systemLineSeparator = System
			.getProperty("line.separator");


			// Mapping table from 6-bit nibbles to Base64 characters.
			private static char[] map1 = new char[64];
			static {
			int i = 0;
			for (char c = 'A'; c <= 'Z'; c++)
			map1[i++] = c;
			for (char c = 'a'; c <= 'z'; c++)
			map1[i++] = c;
			for (char c = '0'; c <= '9'; c++)
			map1[i++] = c;
			map1[i++] = '+';
			map1[i++] = '/';
			}


			// Mapping table from Base64 characters to 6-bit nibbles.
			private static byte[] map2 = new byte[128];
			static {
			for (int i = 0; i < map2.length; i++)
			map2[i] = -1;
			for (int i = 0; i < 64; i++)
			map2[map1[i]] = (byte) i;
			}

			public static String encodeString(String s) {
			return new String(encode(s.getBytes()));
			}

			public static String encodeLines(byte[] in) {
			return encodeLines(in, 0, in.length, 76, systemLineSeparator);
			}

			public static String encodeLines(byte[] in, int iOff, int iLen,
			int lineLen, String lineSeparator) {
			int blockLen = (lineLen * 3) / 4;
			if (blockLen <= 0)
			throw new IllegalArgumentException();
			int lines = (iLen + blockLen - 1) / blockLen;
			int bufLen = ((iLen + 2) / 3) * 4 + lines * lineSeparator.length();
			StringBuilder buf = new StringBuilder(bufLen);
			int ip = 0;
			while (ip < iLen) {
			int l = Math.min(iLen - ip, blockLen);
			buf.append(encode(in, iOff + ip, l));
			buf.append(lineSeparator);
			ip += l;
			}
			return buf.toString();
			}

			public static char[] encode(byte[] in) {
			return encode(in, 0, in.length);
			}

			public static char[] encode(byte[] in, int iLen) {
			return encode(in, 0, iLen);
			}
			public static char[] encode(byte[] in, int iOff, int iLen) {
			int oDataLen = (iLen * 4 + 2) / 3; // output length without padding
			int oLen = ((iLen + 2) / 3) * 4; // output length including padding
			char[] out = new char[oLen];
			int ip = iOff;
			int iEnd = iOff + iLen;
			int op = 0;
			while (ip < iEnd) {
			int i0 = in[ip++] & 0xff;
			int i1 = ip < iEnd ? in[ip++] & 0xff : 0;
			int i2 = ip < iEnd ? in[ip++] & 0xff : 0;
			int o0 = i0 >>> 2;
			int o1 = ((i0 & 3) << 4) | (i1 >>> 4);
			int o2 = ((i1 & 0xf) << 2) | (i2 >>> 6);
			int o3 = i2 & 0x3F;
			out[op++] = map1[o0];
			out[op++] = map1[o1];
			out[op] = op < oDataLen ? map1[o2] : '=';
			op++;
			out[op] = op < oDataLen ? map1[o3] : '=';
			op++;
			}
			return out;
			}
			public static String decodeString(String s) {
			return new String(decode(s));
			}
			public static byte[] decodeLines(String s) {
			char[] buf = new char[s.length() + 3];
			int p = 0;
			for (int ip = 0; ip < s.length(); ip++) {
			char c = s.charAt(ip);
			if (c != ' ' && c != '\r' && c != '\n' && c != '\t')
			buf[p++] = c;
			}
			while ((p % 4) != 0)
			buf[p++] = '0';


			return decode(buf, 0, p);
			}
			public static byte[] decode(String s) {
			return decode(s.toCharArray());
			}
			public static byte[] decode(char[] in) {
			return decode(in, 0, in.length);
			}

			public static byte[] decode(char[] in, int iOff, int iLen) {
			if (iLen % 4 != 0)
			throw new IllegalArgumentException(
			"Length of Base64 encoded input string is not a multiple of 4.");
			while (iLen > 0 && in[iOff + iLen - 1] == '=')
			iLen--;
			int oLen = (iLen * 3) / 4;
			byte[] out = new byte[oLen];
			int ip = iOff;
			int iEnd = iOff + iLen;
			int op = 0;
			while (ip < iEnd) {
			int i0 = in[ip++];
			int i1 = in[ip++];
			int i2 = ip < iEnd ? in[ip++] : 'A';
			int i3 = ip < iEnd ? in[ip++] : 'A';
			if (i0 > 127 || i1 > 127 || i2 > 127 || i3 > 127)
			throw new IllegalArgumentException(
			"Illegal character in Base64 encoded data.");
			int b0 = map2[i0];
			int b1 = map2[i1];
			int b2 = map2[i2];
			int b3 = map2[i3];
			if (b0 < 0 || b1 < 0 || b2 < 0 || b3 < 0)
			throw new IllegalArgumentException(
			"Illegal character in Base64 encoded data.");
			int o0 = (b0 << 2) | (b1 >>> 4);
			int o1 = ((b1 & 0xf) << 4) | (b2 >>> 2);
			int o2 = ((b2 & 3) << 6) | b3;
			out[op++] = (byte) o0;
			if (op < oLen)
			out[op++] = (byte) o1;
			if (op < oLen)
			out[op++] = (byte) o2;
			}
			return out;
			}


			// Dummy constructor.
			private Base64Coder() {
			}
}
